Photoelectric apparatus for measuring the diameter of an inflated flexible casing



Dec. 30, 1947. s. c. HURLEY, JR 2,433,557

PHOTOELECTRIC APPARATUS FOR MEASURING THE DIAMETER OF AN INFLATED FLEXIBLE CASING Filed May 19, 1944 2 Sheets-Sheet 1 9 nun/nee Alp/c0702 x 14 v 2- QF v 1 AMPL/F/ER7 IND/6'4" ivvE/vraka v SAMUEL C HueMr/z 5r 6mm a Want Arm/aways Dec. 30, 194?. s, c, Y, JR 2,433,557

PHOTOELEOTHIC APPARATUS FOR MEASURING THE DIAMETER OF AN INFLATED FLEXIBLE CASING Filed May 19, 1944 2 Sheets-Sheet 2 Ar roe: Y8

Patentfed Dec. 30, 1947 ruo'rontaorrnlc APPARATUS FOR. Measure I .mo. 'rna DIAMETER or AN I'NFLAYTED V I z claimsr 1 m I This invention relates to an improved apparatus for inspecting the diameter offlcxlble turuzxnng CASING 1 sa uei0.1mm,J=..nanvnl,'1n.'- I v v I application May 19. 1944-. serm g if I 4 g I (eras-14) bular casings and more particularly. to a photoelectric sizing mechanism which will measure and indicate the diameter of the flexible casing.

My invention is suitable for measuring and indicating the diameter of any flexible casing and is especially suitable for indicating the size of sausage casings'and the like. The sausage casings tested may be either synthetic or made of animal intestines.

Although either phototubes or photocells may be used in my invention, phototubes are preferable when used in conjunction with the amplifiers shown in Fig. 1. When photocells are used.

ity is preferable to eliminate the amplifiers and the photocells will be connected in conventional form directly to the indicators l5, l6, l1, and I8.

The phototubcs are connected to a conventional amplifying and'indicating mechanism. As the casing varies in size, as shown on the indicating means, it may be cut and sorted by hand or it may be cut and sorted automatically as will be explained later, It may also be cut automatically and sorted by hand.

An object of the invention is to maintain the proper tension on the inflated casing which prevents errors in inspection due to any leakage of the inflating medium from the casing.

There are many advantages of my invention over previous apparatus for the inspection of tubular casings and the like, In my invention, there are no mechanical parts in the actual inspection device which are subject to wear and corrosion. Casings made of animal intestines contain corrosive substances such as salts, fatty acids, etc., which would corrode any inspection device coming directly in contact with the casing If jets of water or other fluid media are jetted over the surface or the natural casing to actuate a switch fordetermining the size of said casings, the fluid will dissolve out the corrosive substances from the casing and these corrosive substances will ruin the switching mechanism. Furthermore, a jet of liquid passing over the suriace of the casing isnot as accurate as the means used in my invention which comprises a beam of light passing over one surface of the inflated casing which casts a shadow on certain of the photoelectric tubes or cells. An additional ad- 'vantage over mechanical or fluid inspection devices is that by my device I can measure a large .number of different diameter casings in the same apparatus without changing any setting which is extremely diflicult if not impossible to do with mechanical or fluid inspection devices.

Other objects and advantages of the invention will appear in the following description of the preferred embodiments of the invention shown in'the attached drawings in which:

' Fig. l is aschematic'drawing showing the mechanical arrangement of the inspection device including the optical systemand indicating device. 3;

Figs. 2 and 3 are diagrammatic views illustrating an optical system for measuring a large number or different sized objects.

Figs. 4 and 5 illustrate specific, means for maintaining the proper inflating tension on the tubular casing during the inspection.

Referring to the drawing, the'device illustrated in Fig. 1 includes a source of light I shown as an electric incandescent lamp, although any other suitable source of concentrated light may be employed. The lamp 1 has its-filament positioned substantially in the optical axis of a pair of condenser lenses 2 for concentrating the light oi the source l.upon the tubular casing being passed through the beam of light from the condenser lenses 2.

A projecting lens 4 is arranged so as to have its optical axis in alignment with the optical axis of the condensing lenses 2 and is positioned upon the opposite side of the test or inspection zone through which the tubular casing 3 is passed. The projecting lens 4 preferably projects a sharply defined shadow of the casing being inspected upon one or more 01' a plurality of photoelectric tubes li, 8, I, and 8, depending upon the diameter of the casing. 7

Although only four photoelectric tubes are shown, any number may be used, depending upon the number of different diameter casings it is desired to test. Generally, one photoelectric tube is needed for each diameter casing to be tested.

By a proper choice of projector lens 4, distance' between lens 4 and the photoelectric cells and tubes in such a manner as to inspect relatively small increments in diameter in the' relatively small diameter range and relatively largefincrements in diameter in the relatively larg diameter range, or vice versa.

In other words. by properly spacing the tubes 5. 6. I, and 8. an inspection may be made for varying increments in diameter for different size casings. The variation in increments measured need not be regular nor constant.

- The photoelectric tubes ll, 8, I. 8, etc.. are connected through seesaw: v

leads or conductors I in a suitable circuit to suitable electronic amplifiers [0, ll, l2, and I3; Amplifiers oithls type are well understood devices and suitable types are procurable on the market. Since the specific construction and details of the amplifiers I0, ll, l2, and I! are not material to the invention. they are illustrated conventionally in the drawinz. The source of electric power to the amplifiers is conventional and is not illustrated.

Amplifiers in. II, l2, and I3 are connected through suitable leads or conductors ll to indicatordevices l5, l6, l1. and II, respectively. The indicating devices l3, l8, l1, and I3 are illustrated conventionally as direct current meters connected in the output circuits of ampliflers I'll, ll, [2, and I3. respectively. Any other suitable indicating devices may be used, such as lights, bells, flags, needles, recording meters, galvancmeters, A. C. meters, etc.

Although separate amplifiers and meters con.- nected to tubes 5, 6, I, and 8 are shown, it is possible to connect tubes 5, 6, I, and 8 to a common amplifier and indication devlce thru a proper common multi-point switch either automaticor hand controlled, connected by leads 9 to the tubes 5, 6. 1, andB.

The method of operation for measuring different diameter casings may be described as follows: If tube 8 is arranged for the smallest diameter casing desired for inspection and such casing 3 is in place, tube 8 will be in shadow and tube 5 will be lighted. By means of amplifier l3, device l8 will indicate that object 3 is of a certain predetermined size. Indicators l5, I6,

I Fl will not be actuated since tubes 5, 6, and I are illuminated. The. casing 3 may increase in size without efiecting indicators l5, l6, and I1 until the next predetermined in size is reached when tube I is cast in shadow by easing 3 and indicator I1 is actuated, indicating the next increment in diameter.

As will be described later, the casings may be out either by hand or automatically and sorted for each change in size.

The casing or flexible tubular object3 is passed in distended or inflated condition through trough 2| by means of squeezing rolls I9 and as'illustrated in Fig; 4. The tension on rolls l9 and '20 is maintained by means of suitable springs properly positioned, such as the springs 22 illustrated in Fig. 6.

.zismeimucaandmasissparusiseeuc vlewaicng line 1-: err-lg. 2, showing the arrangement of the photoelectric tubes. For ease [in following. the same numbers are used in --Figures 2 and 3 and in Fig. 1 wherever possible.

Light source i. condenser lens'2. casing I. positioned in distended or inflated condition in inspection trough 2i. and projection lens 4, are

arranged and function in the same manner as in Fig. 1. The projection lens 4 preferably pro jects a sharply defined shadow of the casing 3 being inspected upon a magnifying mirror 24,

shown as being a cylindrical mirror, although other types of convex or concave mirrors, including a spherical mirror, may be employed,

Photoelectric tubes 21. 28, 29, 3|, and 32 are positioned behind screens 25cm! 26 provided with slots 33, 34, 35, 36, 31 and 38, which per mit an image of the article 3 to be reflected m from mirror 24 through the slots 33, 34, 35, 33, 31

Referring again to Fig. 1, means are partly illustrated for preventing the fluid such as water within the casing from leaking out through poresin the casing with possible harmful contact with the inspection equipment. As mentioned previously, the water within the animal intestinal casings contains dissolved corrosive material and if it should leak or squirt out onto the inspection devices, great harm would occur.

- To prevent or minimize this harmful condition,

and 38, onto one Or more of the photoelectric tubes.

In Fig. 3, shields with slots are provided to mask a portion of the phototubes; however, each tube may be provided with its own mask with the proper opening to expose a portion of the tube.

Only six photoelectric tubes with corresponding slots are shown, but more may be used when desired. In the testing of sausage casings, it is usually desired to measure diameters in 2 millimeter increments from 10 millimeters to 40 which would require 15 tubes with corresponding slots. By using the mirror 24 which enlarges the image of the object being tested, and enclosing the tubes behind screens with corresponding slot openings, it is apparent that the entire range of diameters can be readily inspected in one compact apparatus without the changing of any setting.

Tubes 2'I, 28, 29, 30, 3!, and 32 are connected with suitable amplifiers and indication gages, as illustrated in Fig. 1. As described in connection with Fig. 1, slot 38 has no light passing thru it when the article 3 is of the smallest desired size. Slot 31 has no light passing through it when article 3 is of the next size, and so on.

Referring to Fig. 4, one means of maintaining a flexible or non-rigid tubular casing in distended or inflated condition during the inspection operation is as follows: Casing 3.is passed through squeezing rollers l9, and through pressure plates 39 which maintain pressure on the tube 3 when distended, by means of spring 40.

After a little more of the casing 3 is passed through rollers l9, and before reaching rollers 20, the casing is filled with a fluid and then passed through squeezing rollers 20. Rollers l9 and 20 keep the casing containing the liquid fully distended at all times at its inspection point.

The pressure device 39 is for the purpose of maintaining the casing filled with Water, and distended in inspection position in the trough 2| at all times. Casings made out ofanimal intestines or the like may have pores or holes in them which would permit some of the water in the casing to leak out, in which case, the casing would not be distended for a proper inspection. Pressure deg casing distended, but if they are connected to a suitable power means (not shown), may r0- tate and provide the means for continuously pass- Fig. 4. Where possible, the corresponding parts in Figs. 1 to 3 are numbered the same. Rollers ID are rotatably attached to supporting arm 42, which can pivot about pin 43. Springs 22 maintain the rollers in squeezing position at all times.

'If there is any leakage of the liquid such as water out of the distended casing 3, the casing will be properly distended at the inspection point 4| by means of springs 22.

While I have described and disclosed the pre-' ferred embodiments of my invention, it is understood that the details may be varied and the description is not intended to limit the scope of my invention.

I claim as my invention:

1. An apparatus for inspecting distended flexible casings to ascertain the diameters,'coxnprising a source of light, lens means for projecting light from said source through an inspection zone, a plurality of light sensitive devices positioned to receive said projected light, said inspection zone comprising a trough for receiving and positioning a portion of the length of a distended casing in such manner that the diameter of said 35 1,855,011

casing, a pair of opposed members positioned ad- 40 jacent each end of said trough and arranged to aueeze a casing to prevent passage of fluid from that portion of the casing between said pair of members to adjacent portions thereof, and means {or applying pressure to fluid trapped within 48 came.)

ible casings to ascertain the diameters, comprising a source of light, lens means for projecting light from said source through an inspection zone, a'plurality of light sensitive devices posi- 10 tioned to receive said projected light, said inspection zone comprising a trough for receiving and positioning a portion of, the length of a distended casing in such manner that the diameter of said casing controls the illumination of 15 said light sensitive devices, indicating means responsive to the condition of illumination of said light sensitive'devices for indicating the diameter of said casing, a pair of opposed members positioned adjacent each end of said trough and ar- 0 ranged to squeeze a casing to prevent passage of fluid from that portion of the casing between said pair of members to adjacent portions thereof and to apply pressure to fluid trapped within said casing between said pairs of members in a manner to distend that portion of the casing within said trough.

" SAMUEL C. HURLEY, Ja.

REFERENCES CITED 30 The following references are of record in the flle oi this patent:

UNITED STATES PATENTS Number Name Date DeMoss Apr. 19, 1932 1,963,128 Geister "June 19, 1934 2,085,671 Powers June 29, 1937. 2,187,790 Leavenworth Jan. 23, 1940 2,200,960 Leavenworth May 14, 1940 2,372,162 Ryan Mar. 20, 1945 OTHER REFERENCES I "Die Kunstseide," for 'August 1931, page 283 cited. (Copy in Scientific Library, U. 8. Patent 

